1. Field of the Invention
This invention relates generally to add-on headrests for attaching to vehicle seats.
2. Prior Art
Most vehicles, such as automobiles and airplanes, have seats with integral headrests. Most of such headrests are not adjustable, and are fixed too far back to support a head in a neutral position generally aligned with a torso. A user must lean back to engage the headrest, but such a position is uncomfortable. Further, most built-in headrests lack side bolsters, so that the user is restricted to a vertical position to keep his or her head upright, otherwise it will tend to fall to one side when the user falls asleep.
U.S. Pat. Nos. 313,781 to Starr et al. and 242,380 to Sharp show headrests for attaching to chairs without built-in headrests. However, they require the user to lean back, and are substantially flat, so that they cannot restrain the head from falling to one side. U.S. Pat. Nos. 5,613,736 to Schaked et al.; 5,505,523 to Wang; 4,619,483 to Dickey et al.; 4,339,151 to Riggs; 2,719,577 to Eyman; 2,638,152 to Pulsifer; and 2,587,196 to Morecroft show side bolster headrests for strapping or clamping onto seatbacks. Although they restrain the head from falling to one side, they still require the user to lean back. U.S. Pat. No. 2,464,435 to Conradt shows a headrest with side bolsters which are each adjustable about a vertical axis. However, the side bolsters are vertical, so that they do not conform to the user's face for optimal comfort when the user is leaning sideways. Their height is fixed, so that they do not fit every user. They require three straps to attach to a seat, so that installation is inconvenient. Further, the central cushion for the back of the head is not easily washable or replaceable.